Hi everybody. Today I show you a CW beacon on SI4432 and STM32. Click “More” for details.

For a beacon, youcan use any Maple like board with STM32f103 microcontroler on it.

SI4432 100mW radiomodule with a range of 240-930 MHz is used as the transceiver in the circuit .

Program 1 time per minute sends the wire “CQ CQ UR5TLZ / B” by morse code.

100 mW is enough to hear a beacon within a radius of 600 meters in an area of 9 storey buildings,at this distance squelch of the Baofeng UV5R radio tuner is freely opened by signal of beacon.

If the beacon or recieving station is raised above the ground it is possible to get a greater distance of reception.

The beacon on the third floor, receiving radio station on the ninth floor on the distance of 4,52 km.

Also, the beacon is equipped with a search mode, if on the radio station you press the PTT + the modulated signal (the PTT + BAND button for Baofeng UV5R). The Beacon in response gives three tones of small, medium, and high power, and also gives the word “ECHO” in morse. If you are on long distance, then you will not hear the tone of low power and medium power, if you close to beacon you will hear all three of them. The 9-storey building area it is possible to set beacon in search mode at a distance of 300 meters.